Panel Design / Calculate Size of Bus bar Bus bar Details Bus bar Current Details: Rated Voltage (L-L): Rated Frequency: Desire Maximum Current Rating : Fault Current (Isc): Fault Duration (t):
415 50 630 50 1
Bus bar Temperature Details: Operating Temperature of Bus bar (θ) Final Temperature of Bus bar during Fault(θ1) Temperature rise of Bus Bar Bar during Fault (θt=θ1-θ) Ambient Temperature(θn): Maximum Bus Bar Temperature Rise:
85 185 100 50 35
Enclosure Detail: Type of Panel Installation of Panel Altitude of Panel Installation on Site Panel Length
Cubical Type Indoors (well Ventilated) 2200 1200
Panel W idth
600
Panel Height
2400
Panel Area:
1728000000
Bus bar Detail: Bus bar Material Bus bar Shape Bus bar Strip Arrangements Current Density of Bus Bar Material Temperature Co efficient of Material Resistance at 20°c(α20): Material Constant(K): # Bus bar Material Permissible Strength: Bus bar Insulating Material: Bus bar Position: Bus bar Installation Media: Bus bar Artificial Ventilation Scheme:
Copper Flat Bars Vertical 1.6 0.00403 1.166 1200 Ba r e
Edge-mounted bars Non-ventilated ducting without artificial ventilation
Bus bar Size Detail: Busbar W idth(e):
75
Busbar Thickness(s):
10
Number of Bus Bar per Phase(n): Total Busbar Area per Phase: Busbar Length per Phase(a): Distance between Two Bus Strip per Phase(e): Busbar Phase Spacing (p): Total width of Bus bar per Phase(w): # Busbar Phase to Phase Distance (d): Modulus of inertia of a busbar or of a set of busbars Total No of Circuit Total Busbar Area for Enclosure
Busbar Support Insulator Detail:
2 1500 500 75 400 225 625 14.45 3 9000000
# Distance between insulators on Same Phase(l): # Insulator Height (H) Distance from the head of the insulator to the busbar centre of 1 gravity (h): # Permissible Strength of Insulator (F'):
Indoors (well Ventilated) Indoors (Poorly Ventilated) Outdoor Flat Bars Round Bars Hollow Round Bars Bare PVC Sleeving Painted Edge-mounted bars 1 bar base-mounted several base-mounted bars Calm indoor atmosphere Calm outdoor atmosphere Non-ventilated ducting without artificial ventilation with artificial ventilation Horizontal Vertical
500 100 5 1000
Jignesh.Parmar, www.electricalnotes.wordpress.com,jiguparma
[email protected]
Bus bar Size Calculation De rating Factors Volt Hz Amp KA Sec
Per Phase Bus Strip De rating Factor (K1) Busbar Insulating Material De rating Factor (K2) Busbar Position De rating Factor (K3) Busbar Installation Media De rating Factor (K4) Busbar Artificial Ventilation De rating Factor (K5)
1.83 1 1 0.8 0.9
Enclosure & Ventilation De rating Factor (K6)
0.95
°c °c °c
Proxy Effect De rating Factor (K7) Altitude of Bus Bar installation De rating Factor (K8) Total Derating Factor:
0.82 0.88 0.90
°c °c
Busbar Size Calculation
2 Meter mm
Desire Current Rating of Busbar (I2)
630
Current Rating of Busbar after Derating Factor (I1) Busbar Cross Section Area as per Current Busbar Cross Section Area as per Short Circuit
697 436 626
Final Calculated Bus Bar Cross Section Area
626
Actual Cross Section Area of Busbar
1500
mm
Bus Bar Size is OK
mm
Forces generated on Bus Bar due to Short Circuit Current
Sq.mm
Peak electro-magnetic forces between phase conductors (F1)
250
Peak electro-magnetic forces between phase conductors (F1)
2.5
Forces at the head of the Supports or Bus Bar (F) Permissible Strength of Insulator (F') is
3 10
Forces on Insulation is in within Limits A/Sq.mm
Mechanical strength of the busbars
Kg/cm2
Mechanical strength of the busbars Mechanical strength of the busbars Permissible Busbar Strength is
72 0.7 12
Mechanical strength of Busbar is in within Limit Temperature Rise Calculation Specified Maximum Temperature Rise (T1) Calculated Maximum Temperature Rise (T2)
Temperature Rise is in within Limit mm mm
Results:
No's Sq.mm mm mm mm mm mm cm3
Size of Busbar: 2 Nos X 75 X 10 Per Phase Total No's of Busbar: 6 Nos X 75 X 10 for Phase and 1 Nos X 75 X 10 Per Neutral Forces at the head of the Supports or Bus Bar (F) :2.625Kg/mm 2 Mechanical strength of the busbars :0.7Kg/mm2 Maximum Temperature Rise :30°c
Sq.mm
35 30
mm mm mm Kg/cm2 Ref: Merlin Gerin design guide
m
0.15
0.52% 2
Amp Amp Sq.mm Sq.mm
Sq.mm Sq.mm
Kg/cm2 Kg/mm2 Kg/mm2 Kg/mm2
Kg/cm2 Kg/mm2 Kg/mm2
°c °c
1
Various Derating Factor Number of Bus bar Strip per Phase (K1) e/a
No of Bus bar per Phase 2 1.63
0.05
1 1
3 2.4
0.06
1
1.73
2.45
0.08 0.1 0.12
1 1 1
1.76 1.8 1.83
2.5 2.55 2.6
0.14
1
1.85
2.63
0.16 0.18 0.2
1 1 1
1.87 1.89 1.91
2.65 2.68 2.7
Volume of Enclosure & Ventilation De rating Factor (K6) cross Section area of Busbar/Total Bus bar Area 0%
Indoors ( Panel is well Ventilated) 0.95
Indoors ( Panel is Poorly Ventilated) 0.85
1% 5% 10%
0.95 0.9 0.85
0.85 0.7 0.65
Value of Modulus of inertia of a bus bar or of a set of bus bars (i/v) No of Bus Strip per Phase 1 2 3
Vertical Bus Bar (cm3) 1.66 14.45 33
Horizontal Bus Bar (cm3) 16.66 33.33 50
Outdoor 0.65 0.65 0.6 0.5
2 2 14.45
Bus bar Insulating Material (K2): Bare PVC Sleeving Painted
De rating Factor 1 1.2 1.5
Bus bar Position(K3): Edge-mounted bars 1 bar base-mounted several base-mounted bars
Bus bar Installation Media(K4): Calm indoor atmosphere Calm outdoor atmosphere Non-ventilated ducting
Bus bar Artificial Ventilation Scheme (K5): without artificial ventilation with artificial ventilation
De rating Factor 1 0.95 0.75
De rating Factor 1 1.2 0.8
De rating Factor 0.9 1
Altitude of installation site (Meter) (K8)
De rating Factor
2200 2400 2500 2700
0.88 0.87 0.86 0.85
2900
0.84
3000 3300 3500 4000 4500 5000
0.83 0.82 0.81 0.78 0.76 0.74
Proxiy Effect (K7): 1 2 3 4 5 6 7
De rating Factor 0.82 0.82 0.82 0.89 0.95 0.99 1
